Apron for drum driers



May l2, 1959 G. ovERToN 2,386,101 APRoN FOR DRUM DRIERS Filed Deo. s1, 1952 l s sheets-sheet 1 IWI/*E TTZZLDT May 12, 1959 G. OVERTON' 2,886,101

l APRON FOR DRUM DRIERS Filed Dec. :51, 1952 s sheets-sheet s United States y Patent O 2,886,101 APRON Fon DRUM nnlnns Glen Overton, Allegan, Mich. Application December 31, 1952,\`Serial N0.328,865 8 Claims. (Cl. 159-11) 'j This invention relates generally to a conveying apron apparatus attachable to or mounted in a vacuum-type drum drying machine, and more particularly to a water cooled-type apparatus incorporating features ofmaterial advantage in receiving dried material discharged from a heated drying drum.

`Drumdrying machines comprise generally a rotary drying element such as a heated drum, having a portion of its peripheral `surface communicating with a trough containing material to be dehydrated or dried, `a scraper element to remove the coating of material formed during theldrying process and adhering to the outer cylindrical surface fof thedrum, and a material `handling device, such as `an inclined apron, to deflect the dry product as it is removed fromthe cylinder by the scraper blade into a conveyor or receptacle of some kind. In this operation, there is a tendency for the dried film to be overheated and cooked due to the residual heat in the material afterthe drying operation has been completed. It has been found that this residual heat continues to cook the material after` the dehydration process has 'been completed with the result that caramelizing sets in and the material is rendered useless.

To the end that the above indicateddiiiculty may be avoided, and as an important' object of the invention,

there is provided an improved Water cooled conveying apron to overcome this objectionable action wherein the dehydrated film is effectively cooled immediatelyupon its removal from the hot dehydrating drum. With this end in view, it is possible for a dehydrated film of materialto be deprived of its residual heat and thereby afford easy removal from `the drying drum, and at the same time facilitate the progression of the dried film.

Accordingly, the present invention is directed toward and has as an object the provision of a water cooled type drum drier apron combination incorporating improved features ofconstruction affording means to `remove residual heat from and to deflect the dry product as it `is removed from the drum drier into `a conveyor or receptacle of some kind.

Another object of the present invention is to provide awater-cooled-type implement attachment including parts constructed and combined for coaction with each other `in an improved manner for imparting a simple reciprocating drive motion thereto, and for eliminating the provision of separate means for preventing the adherence of dry material to the conveying apron.

Still another object of this invention is to provide an improved form of conveying apron such as a crimped or corrugated apron for conveying dry material to a receptacle with a minimum of surface contact whereas in some instances, for example, the dried material has form of water-cooled apron which may be used in the` 2,886,101 `Patented May 12, ..1 959 With these and other objects `in View,` it will become Figure 2" is a side elevationalview of the apparatus with parts broken away toshow underlying parts;

Figure 3 is an enlarged sectional` view of the conveying apron and mounting assembly therefor, takenalong the line III-III of Figure 2; i i

`Figure 4 is a bottom plan View of `the conveying apron assembly of FigureI 3 `showing the drive mechanism;4 l

` Figure 5 is a horizontal sectional View of the `conveying apron taken along the line V-V of Figure 3 and showing details` of the baiiie-type cooling system;

t Figure` is an enlarged end elevational View of a fragmentary part of the apparatus of Figure 2 showing details of the apron adjusting mechanism; t

Figure 7 is anenlarged sectional view of a modied apparatus of Figurel;` j

Figure 8 is a horizontal sectional view of the modied apron shown in Figure 7; i i

Figure 9 is an enlarged sectional view of the modified apron, taking `along the line IX-IX of Figure 8; and

Figure 10 is a diagrammatic sketch showing further details of the apron adjusting mechanics.

As shown on the drawings:

In Figures l and 2 numeral 10 designates. a vacuumtype housing or receptacle equipped in accordance with this invention. Receptacle 10 which is gas-tight consists `of a cylindrical body 11,` end heads or plates 1'2, and a vacuum exhaust outlet opening 13, adapted to be connected `to a vacuumpump (not shown) for evacuating air from the receptacle tank.

Referring particularly to Figure 1, numeral` 15 desig-1 nates cylindrical `drier drums which` may betrotated by a power unit not shown in the drawings. The drums 15` cooperate to define a nip trough 14 therebeteween andA are internally heatedby steam. Numeral1`6` designates the inlet or feed pipe to the nip trough between `the j drums, for feed of liquid or slurry to be dried such as milk, distilling waste slurry, `food slurries and the like.`

` In Figure l, the illustrated left-hand drum 15 rotates clockwise andthe right-hand drum 15 rotates counter` surfaces of these drums "are dried and scraped olf of the drums by scraper blades 16a, commonly referred to as` doctor blades. The dried iilrns from the scraper or doctor blades `are ydeposited on inclined plate aprons 17.of`

this invention. f `The `apronsl17 support and guide` the iilins` such as (Figure 3) to troughs 18 carried by brackets 18a and equipped with screw conveyors 19. The conveyors 19 break the films intopliakes or powder form and move the material to discharge outlet 20at the front end ofthe housing, 4

The conveying apron 17 consists of a hollow cooling box` or tray formed of sheet metal or other good heat transferand rigid material. The box or tray has a bottom i wall 28, endandside walls 29, and an apron plate cover 27 supported by and secured to thetop edges of the side and end walls to form a sealing it therewith in the manner illustrated in Figure 3. Within the cooling box formed by thebottorn wall 28 and the end and side walls 29 are a series of baffle plate 30 secured to the bottom 28 and t tightly abutting the top wall or cover plate Z7, each batlie plate being of a length shorter than the length of the cooling box and each having one end thereof secured alternatingly to opposite end walls 29 to form the baille plates in parallel. and staggered relation, as clearly indicated in Figure 5, whereby liquid coolant such as water'entering inlet pipe 31 is forced to followA a winding serpentine path beforeit leaves outletV pipe 32. It is to be understood thatwhereas in the embodimentlillustrated' the cooling water is shown as flowing in one direction, the conveying apron `is equally adapted to perform its cooling function with a reverse flow of cooling water.

The `apron box or tray carries rollers` 33 on the bottom V thereof which ride on a supporting frame 21. The supporting frame is of rectangular form consisting of cross bars 23 rigidly connected to angle beams 22. These angle beams iixedly carry U-tracks 22a within which rollers 33 are adapted to roll. In this way the apron may travel back and forth on rollers supported by the frame 21.

Each supportingv frame 21 is hingedly secured along its ilower edge to the adjacent wall of trough 18 at 54 and may be swung away from drum by manipulation of a,

control handle or lever34 (Fig. 2) next to be described. Handle 34, which is mounted externally and which is accessible' from the outside of the sealed chamber, is formed integral with a rock shaft 55. This rock shaft, which is journalled in support brackets 46 secured to the wall of trough 18, has secured or welded along the lengths thereof spaced bell crank arms or lifting lingers 47 equipped with rollers 48 contacting the underside of cross bars 23. Swinging of handle 34 about rock shaft 55 as a pivot rotates bell crank arm 47 so as to either pivotally raise or lower the supporting frame 21 about its hinge axis 54. The supporting frame is held in adjusted' position by means of a pin 49 tting in an aperq ture at the end of handle 34 Vand in a selected one of the apertures 50 in sector plate 51, which sector plate is secured to the outside of end plate 12. The particular angular adjustment of the apron carriage which may be required or desired is dependent on the specific material or slurry being dried and varies for different products. It has been found that in general, a flat angle is the best angle of application for slow but steady delivery of dried material.

The conveying apron is reciprocatingly driven by means of an electric rnotor 37a, whoseconstantly rotating drive shaft 37 haseccentrically mounted thereon a cam 38 for moving a roller follower arm 39 in a linear direction parallel to the axis of the drier drum. Theroller follower arm has a threaded arm 40, a cam roller 40a` mounted at one end of the arm, stop nuts 44 and 44a, and contact springs 45` and 45a. The arm 40 is freely slidable on suitable support structure such as through aligned openings 41 in cross plates 24 and 24a, so that spring 45 can act against the cross plate 24 of the apron to move the apron in one direction, and spring 45a can act against plate 24a to move the apron in the other direction. Either the support structure or plates 24 and 24a may be generally identified herein as support plate structure. A pair of springs 42, each having one end rigidly secured to the body 11 or end wall 12 and having its other end connected to the cross plates, urge the apron in the direction of the drive shaft 37 and insure constant contact between the cam and cam roller.

In this manner the eccentrically mounted rotating cam imparts to the apron carriage a reciprocating agitating motion, similar to the sifting motioncommonly associated with a sieve, and the distance through whichV the apron carriage reciprocatingly moves is controlled by lock nuts 4.4 and 44a. Y .Y

The eccentrically mounted cam `38 is of cylindrical form,` and of suicient length so that inV all positions of the rockable apron about its hinge axis, the cam followerv roller 40a will'be in contact with cam 38, thus, preventing the apronV from riding over Athe cam when the apron is swungY upwardlyawayfromthe drum. l

In order to allow for agitation of the Water-cooled conveying apron, and at the same time provide cooling water therefor, the inlet andoutlet cooling water tubes 34 and 35, respectively, are connected to their associated inlet and outlet pipes 31 and 32 by means of flexible couplings 36, such as, for example, soft rubber tubing or hose.

From the above description it may be seen that this invention provides a continuous flow of cooling water to a conveying apron which is in constant agitation by reason of the operation of` the'drive arrangement described hereinabove. This machine is particularly useful in drying material without burning the material or imparting a boiled or cooked avor thereto.

It will be understood that modications and variations may be effected without departing from the scope of the novel concepts of the present invention. For example, in the modified form of apron carriage illustrated in.Figures 7, 8 and 9, the cooling water apron box may be constituted of a pair of crimped or corrugated sheets of she'et metal, 56 and 57, in opposed relation and secured together to form a series of parallel conduits each connected to one another at the ends by U-type pipe bends 58, in the manner shown in Figure 8 to form a winding path for cooling water to follow without departing from the spirit or scope of the instant invention.

In the modified form of invention illustrated in Figures 7, 8 and 9, the upper apron sheet 57, presents a minimum of surface contacts to the film of dried material, and'` hence is particularly useful Where the dried material has gummy or sticky characteristics. Also, in the modied version the apron rollers 33 may be dispensed with, and,

round head cap screws 43 provided in lieu thereof, whereby, through the action of cam 38 and springs 42 on` crossplates 24 and 24a the apron may slide along tracks or guides 44 welded to beam 22 in the identical manner that the preferred form of water cooled apronl is reciprocatingly rolled therealong.

From the above description it will therefore be understood that cooledv reciprocating aprons are provided forl drum driers to prevent overheating of dried lms While directing these films from the drums` to a discharge mechanism.

I claim as my invention: v l. In a vacuum drum drying apparatus having a ro,

apron may be adjusted'to vary the rate of ilow thereover, means for adjustably swinging said apron, means for.

cooling said apron, a pair of cross plates connected tothe underside of the apron, said cross plates having,

aligned openings for freely receiving the arm. of a roller follower arm, 'an eccentrically driven cam for actuating said roller follower arm in one direction, means urging said rollerfollower arm in the oppositeV direction, a

pair` of stop nuts threaded on said arm, and` spring meansA disposed between said stop nutsfor assisting in thereciprocation of the apron, said cross plates beingdisposed between said stop` nuts whereby upon actuation of said roller Vfollower arm in-one direction, one of said stop nuts will cooperate with said spring means and urge the apron in said one direction, and upon actuation in the reverse direction, the other of said stop nuts will cooperate with said spring means and impart. reverse motion to said apron.

2. In a vacuum drum drying apparatus having a rotatable drier drum, the improvements whichA comprise a rockablymounted lconveying apron for disposition in proximity to the cylindrical surface of the drum extend-` ing along the length of the drum and having ay pivotal axis by means of which the angle of inclination ofI the apron may be adjusted to vary the rate of flow thermen,

means for adjustably swinging said apron, means for cooling said apron, said last mentioned means comprising a box of labyrinth construction disposed below said apron, said box having on opposite sides thereof a water inlet and water outlet opening, whereby said labyrinth construction effectively battles said cooling water along a snake-like path, flexible water hose connections adjacent said openings to permit agitation of said apron, means for lagitating said apron including a plurality of cross plates connected to the underside of the apron, said cross plates having aligned openings for freely receiving the arm of a roller follower arm, an eccentrically driven cam for actuating said roller follower arm in one direction, means urging said roller follower arm in the opposite direction, a pair of stop nuts threaded on said arm, and spring means disposed between said stop nuts for assisting in the reciprocation of the apron, said cross plate being disposed between said stop nuts, whereby upon actuation of said roller follower arm by said cam in one direction, one of said stop nuts will urge the apron in one direction and upon actuation in the` reverse direction the other of said stop nuts will impart reverse motion to the apron.

3. In a vacuum drum drying apparatus having a rotatable drier drum, the improvements which comprise a rockably mounted conveying apron for disposition in proximity to the cylindrical surface of the drum extending along the length of the drum and having a pivotal axis by means of which the angle of inclination of the apron may be adjusted to vary the rate of ow thereover, f

means for adjustably swinging said apron, means for cooling said apron, said last mentioned means comprising a container of labyrinth construction disposed below said apron, said container having a water inlet and water outlet opening, whereby said labyrinth constmction effectively bales said cooling water along a snake like path, flexible water hose connections adjacent said openings to permit agitation of said apron, means for agitating ysaid 'apron including `a pair of cross plates connected to the underside of the apron, said cross plates having aligned openings for freely receiving the arm of a roller follower arm, an eccentrically driven cam for actuating said roller follower arm in one direction, means urging said roller follower ann in the opposite direction, a pair of stop nuts threaded on said arm, and spring means disposed between said stop nuts for assisting in the reciprocation of the apron, said cross plates being disposed between said stop nuts, whereby upon actuation of said roller follower arm by said cam in one direction, one of said stop nuts will urge the apron in one direction and upon actuation in the vreverse direction the other of said stop nuts will impart reverse motion to the apron.

4. In a vacuum drum ldrying apparatus having a rotatable drier drum, the improvements which comprise a conveying apron for disposition in proximity to the drum, means for agitating the apron including a pair of spaced extensions, said extensions having aligned openings for freely receiving the arm of a roller lfollower arm, an eccentrically driven cam for actuating said roller follower arm in one direction, means urging said roller follower arm in the opposite direction, -a pair of stop nuts threaded on said arm, and spring means cooperable with said stop nuts for assisting in the reciprocation of the apron, said extensions being disposed between said stop nuts whereby upon actuation of said roller follower arm in one direction, one ofv said stop nuts will urge the apron in one direction, and upon actuation in the reverse direction, the other of said stop nuts will impart reverse motion to said apron.

5. The apparatus of claim 4 further characterized by the apron including a corrugated sheet providing a surface adapted to receive dried film material thereover, and means for cooling said sheet.

6. The apparatus of claim 4 further characterized by a pair of corrugated sheets secured together for defining a plurality of passages therebetween, and means for flowing liquid coolant through said passages.

7. In a drum drying apparatus, a rotatable drier drum carried on the apparatus, a conveying apron connected to the apparatus for disposition in proximity to the drum, actuating means reciprocating the apron axially of the drum including support plate structure, said actuating means including a roller follower arm connected to the plate structure, and said actuating means including means for actuating said roller follower arm back and forth, said actuating means also including stops on opposite sides of said support plate structure whereby upon actuation of said roller follower arm in one direction, one of said stops will cooperate with the actuating means and urge the apron in one direction, and upon actuation in the reverse direction, the other of said stops will cooperate with the actuating means and will impart reverse motion to said apron.

8. The drum drying apparatus of claim 7 lfurther characterized by means for water cooling the apron, said last mentioned means comprising a water sealed box labyrinth construction having a water inlet and a water outlet opening, and providing a snake-like path for cooling between the inlet and the outlet, and flexible water hose connections adjacent said openings to permit reciprocation of said apron.

References Cited in the file of this patent UNITED STATES PATENTS 139,556 Eames June 3, 1873 505,723 Pollock Sept. 26, 1893 711,719 Ekenberg Oct. 21, 1902 1,011,680 Wall Dec. 12, 1911 1,047,760 Davidson Dec. 17, 1912 1,081,338 Sleeper Dec. 16, 1913 1,353,980 Yahn Sept. 28, 1920 1,775,819 Fischer et al Sept. 16, 1930 2,082,819 Beccard June 8, 1937 2,131,666 McDougall Sept. 27, 1938 2,157,339 Jeffery May 9, 1939 2,170,396 Banbury Aug. 22, 1939 2,235,324 Moreland Mar. 18, 1941 2,352,220 Overton lune 27, 1944 2,391,033 Northcutt et al. Dec. 18, 1945 2,395,089 Arelt Feb. 19, 1946 

